Sex in mammals is genetically determined; females normally have two X chromosomes, and males normally have one X and one Y chromosome. But sometimes an individual with two X chromosomes is born with male genitalia, in a case of XX male sex reversal. The incidence of XX male sex reversal in humans is roughly 1ContinueContinue reading “Sex reversal linked to Sox3”
Tag Archives: genetics & genomics
Variation, selection and adaptation in fruit flies
Various studies have been done to analyze the genomics of adaptation in response to selective pressures, mostly using asexual organisms with relatively small genomes, such as bacteria. Now, a new study has looked at this process in a sexually reproducing organism—the tiny fruit fly (Drosophila melanogaster). Lab Anim. (NY) 39, 330 (2010). view full textContinueContinue reading “Variation, selection and adaptation in fruit flies”
Losing a gene, regaining lost tissue
Tissue regeneration may be common in certain species but is rare in mammals. Typical mammalian healing involves scar formation, and scar tissue is quite different from the original tissue that it replaces. Regeneration, on the other hand, involves formation of a blastema, a group of cells capable of rapid growth that recreates missing tissue. RegenerationContinueContinue reading “Losing a gene, regaining lost tissue”
New chromosome, new species
The formation of new species is typically driven by environmental adaptation. But a recent investigation of neighboring populations of threespine stickleback fish (Gasterosteus aculeatus) has now shown, for the first time, that creation of a new sex chromosome can contribute to speciation. Lab Anim. (NY) 38, 341 (2009). view full text (login required)
Better cloning for zebrafish
Zebrafish are popular models for studies of genetics, development and diseases such as cancer and cardiovascular disorders. To increase their utility in biomedical research, scientists have worked to develop methods of gene manipulation in zebrafish. Previous attempts have had limited success, but Jose Cibelli and colleagues (Michigan State University, East Lansing) have now refined aContinueContinue reading “Better cloning for zebrafish”
Marsupial genomics bounds along
Australian genomics has taken a big step forward with the completion of the genome map of the tammar wallaby. The wallaby (Macropus eugenii) is the first kangaroo species to have its genome mapped and sequenced. Researchers at the Australian Research Council Centre of Excellence for Kangaroo Genomics (KanGO), based in Canberra, constructed the genome map,ContinueContinue reading “Marsupial genomics bounds along”
Genetic association gone to the dogs
After the complete sequence of the dog genome was determined in 2005, geneticists proposed that it would be useful for finding the locations of genes associated with various inheritable traits. Domestication and breeding have made the genetic structure of the dog ideal for this application: dogs of the same breed have long stretches of identicalContinueContinue reading “Genetic association gone to the dogs”
In the running with ACTN3
Researchers in Australia recently reported a polymorphism in ACTN3, encoding α-actinin-3, associated with sprint versus endurance performance among elite athletes. The report raises the idea that genetic differences, such as that in ACTN3, could be useful predictors of athletic performance at the elite level, although such potential has not been established. Nat. Genet. 35, 123ContinueContinue reading “In the running with ACTN3”
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